package org.apache.maven.model.management;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

import org.apache.maven.model.Build;
import org.apache.maven.model.Model;
import org.apache.maven.model.Plugin;
import org.apache.maven.model.PluginContainer;
import org.apache.maven.model.PluginExecution;
import org.apache.maven.model.PluginManagement;
import org.apache.maven.model.building.ModelBuildingRequest;
import org.apache.maven.model.building.ModelProblemCollector;
import org.apache.maven.model.merge.MavenModelMerger;
import org.codehaus.plexus.component.annotations.Component;

/**
 * Handles injection of plugin management into the model.
 *
 * @author Benjamin Bentmann
 */
@Component(role = PluginManagementInjector.class)
public class DefaultPluginManagementInjector implements PluginManagementInjector {

  private ManagementModelMerger merger = new ManagementModelMerger();

  public void injectManagement(Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
    merger.mergeManagedBuildPlugins(model);
  }

  protected static class ManagementModelMerger extends MavenModelMerger {

    public void mergeManagedBuildPlugins(Model model) {
      Build build = model.getBuild();
      if (build != null) {
        PluginManagement pluginManagement = build.getPluginManagement();
        if (pluginManagement != null) {
          mergePluginContainer_Plugins(build, pluginManagement);
        }
      }
    }

    private void mergePluginContainer_Plugins(PluginContainer target, PluginContainer source) {
      List<Plugin> src = source.getPlugins();
      if (!src.isEmpty()) {
        List<Plugin> tgt = target.getPlugins();

        Map<Object, Plugin> managedPlugins = new LinkedHashMap<Object, Plugin>(src.size() * 2);

        Map<Object, Object> context = Collections.emptyMap();

        for (Plugin element : src) {
          Object key = getPluginKey(element);
          managedPlugins.put(key, element);
        }

        for (Plugin element : tgt) {
          Object key = getPluginKey(element);
          Plugin managedPlugin = managedPlugins.get(key);
          if (managedPlugin != null) {
            mergePlugin(element, managedPlugin, false, context);
          }
        }
      }
    }

    @Override
    protected void mergePlugin_Executions(Plugin target, Plugin source, boolean sourceDominant,
        Map<Object, Object> context) {
      List<PluginExecution> src = source.getExecutions();
      if (!src.isEmpty()) {
        List<PluginExecution> tgt = target.getExecutions();

        Map<Object, PluginExecution> merged = new LinkedHashMap<Object, PluginExecution>((src.size() + tgt.size()) * 2);

        for (PluginExecution element : src) {
          Object key = getPluginExecutionKey(element);
          merged.put(key, element.clone());
        }

        for (PluginExecution element : tgt) {
          Object key = getPluginExecutionKey(element);
          PluginExecution existing = merged.get(key);
          if (existing != null) {
            mergePluginExecution(element, existing, sourceDominant, context);
          }
          merged.put(key, element);
        }

        target.setExecutions(new ArrayList<PluginExecution>(merged.values()));
      }
    }
  }

}
